syscall: support Getwd on all BSDs

All supported BSDs provide the SYS___GETCWD syscall which can be used to implement syscall.Getwd. With this change os.Getwd can use a single syscall instead of falling back to the current kludge solution on the BSDs. This doesn't add any new exported functions to the frozen syscall package, only ImplementsGetwd changes to true for dragonfly, freebsd, netbsd and openbsd. As suggested by Ian, this follows CL 83755 which did the same for golang.org/x/sys/unix. Also, an entry for netbsd/arm is added to mkall.sh which was used to generate the syscall wrappers there. Change-Id: I84da1ec61a6b8625443699a63cde556b6442ad41 Reviewed-on: https://go-review.googlesource.com/84484 Reviewed-by: Ian Lance Taylor <[email protected]>
2bt · Feb 13, 2018 · acd17e9 · acd17e9
1 parent dc27d68
commit acd17e9
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Showing 34 changed files with 292 additions and 20 deletions.
diff --git a/api/except.txt b/api/except.txt
@@ -15,25 +15,30 @@ pkg syscall (darwin-amd64-cgo), func Fchflags(string, int) error
 pkg syscall (freebsd-386), const AF_MAX = 38
 pkg syscall (freebsd-386), const DLT_MATCHING_MAX = 242
 pkg syscall (freebsd-386), const ELAST = 94
+pkg syscall (freebsd-386), const ImplementsGetwd = false
 pkg syscall (freebsd-386), const O_CLOEXEC = 0
 pkg syscall (freebsd-386), func Fchflags(string, int) error
 pkg syscall (freebsd-386-cgo), const AF_MAX = 38
 pkg syscall (freebsd-386-cgo), const DLT_MATCHING_MAX = 242
 pkg syscall (freebsd-386-cgo), const ELAST = 94
+pkg syscall (freebsd-386-cgo), const ImplementsGetwd = false
 pkg syscall (freebsd-386-cgo), const O_CLOEXEC = 0
 pkg syscall (freebsd-amd64), const AF_MAX = 38
 pkg syscall (freebsd-amd64), const DLT_MATCHING_MAX = 242
 pkg syscall (freebsd-amd64), const ELAST = 94
+pkg syscall (freebsd-amd64), const ImplementsGetwd = false
 pkg syscall (freebsd-amd64), const O_CLOEXEC = 0
 pkg syscall (freebsd-amd64), func Fchflags(string, int) error
 pkg syscall (freebsd-amd64-cgo), const AF_MAX = 38
 pkg syscall (freebsd-amd64-cgo), const DLT_MATCHING_MAX = 242
 pkg syscall (freebsd-amd64-cgo), const ELAST = 94
+pkg syscall (freebsd-amd64-cgo), const ImplementsGetwd = false
 pkg syscall (freebsd-amd64-cgo), const O_CLOEXEC = 0
 pkg syscall (freebsd-arm), const AF_MAX = 38
 pkg syscall (freebsd-arm), const BIOCGRTIMEOUT = 1074545262
 pkg syscall (freebsd-arm), const BIOCSRTIMEOUT = 2148287085
 pkg syscall (freebsd-arm), const ELAST = 94
+pkg syscall (freebsd-arm), const ImplementsGetwd = false
 pkg syscall (freebsd-arm), const O_CLOEXEC = 0
 pkg syscall (freebsd-arm), const SIOCAIFADDR = 2151967019
 pkg syscall (freebsd-arm), const SIOCGIFSTATUS = 3274991931
@@ -65,6 +70,7 @@ pkg syscall (freebsd-arm-cgo), const AF_MAX = 38
 pkg syscall (freebsd-arm-cgo), const BIOCGRTIMEOUT = 1074545262
 pkg syscall (freebsd-arm-cgo), const BIOCSRTIMEOUT = 2148287085
 pkg syscall (freebsd-arm-cgo), const ELAST = 94
+pkg syscall (freebsd-arm-cgo), const ImplementsGetwd = false
 pkg syscall (freebsd-arm-cgo), const O_CLOEXEC = 0
 pkg syscall (freebsd-arm-cgo), const SIOCAIFADDR = 2151967019
 pkg syscall (freebsd-arm-cgo), const SIOCGIFSTATUS = 3274991931
@@ -98,6 +104,12 @@ pkg syscall (linux-amd64), type Cmsghdr struct, X__cmsg_data [0]uint8
 pkg syscall (linux-amd64-cgo), type Cmsghdr struct, X__cmsg_data [0]uint8
 pkg syscall (linux-arm), type Cmsghdr struct, X__cmsg_data [0]uint8
 pkg syscall (linux-arm-cgo), type Cmsghdr struct, X__cmsg_data [0]uint8
+pkg syscall (netbsd-386), const ImplementsGetwd = false
+pkg syscall (netbsd-386-cgo), const ImplementsGetwd = false
+pkg syscall (netbsd-amd64), const ImplementsGetwd = false
+pkg syscall (netbsd-amd64-cgo), const ImplementsGetwd = false
+pkg syscall (netbsd-arm), const ImplementsGetwd = false
+pkg syscall (netbsd-arm-cgo), const ImplementsGetwd = false
 pkg syscall (netbsd-arm), const SizeofIfData = 132
 pkg syscall (netbsd-arm), func Fchflags(string, int) error
 pkg syscall (netbsd-arm), type IfMsghdr struct, Pad_cgo_1 [4]uint8
@@ -106,6 +118,7 @@ pkg syscall (netbsd-arm-cgo), func Fchflags(string, int) error
 pkg syscall (netbsd-arm-cgo), type IfMsghdr struct, Pad_cgo_1 [4]uint8
 pkg syscall (openbsd-386), const BIOCGRTIMEOUT = 1074283118
 pkg syscall (openbsd-386), const BIOCSRTIMEOUT = 2148024941
+pkg syscall (openbsd-386), const ImplementsGetwd = false
 pkg syscall (openbsd-386), const RTF_FMASK = 63496
 pkg syscall (openbsd-386), const RTM_VERSION = 4
 pkg syscall (openbsd-386), const SIOCBRDGDADDR = 2150132039
@@ -158,6 +171,7 @@ pkg syscall (openbsd-386), type Timespec struct, Sec int32
 pkg syscall (openbsd-386), type Timeval struct, Sec int32
 pkg syscall (openbsd-386-cgo), const BIOCGRTIMEOUT = 1074283118
 pkg syscall (openbsd-386-cgo), const BIOCSRTIMEOUT = 2148024941
+pkg syscall (openbsd-386-cgo), const ImplementsGetwd = false
 pkg syscall (openbsd-386-cgo), const RTF_FMASK = 63496
 pkg syscall (openbsd-386-cgo), const RTM_VERSION = 4
 pkg syscall (openbsd-386-cgo), const SIOCBRDGDADDR = 2150132039
@@ -220,6 +234,7 @@ pkg syscall (openbsd-amd64), const EFER_NXE = 2048
 pkg syscall (openbsd-amd64), const EFER_NXE ideal-int
 pkg syscall (openbsd-amd64), const EFER_SCE = 1
 pkg syscall (openbsd-amd64), const EFER_SCE ideal-int
+pkg syscall (openbsd-amd64), const ImplementsGetwd = false
 pkg syscall (openbsd-amd64), const PMC5_PIPELINE_FLUSH = 21
 pkg syscall (openbsd-amd64), const PMC5_PIPELINE_FLUSH ideal-int
 pkg syscall (openbsd-amd64), const RTF_FMASK = 63496
@@ -282,6 +297,7 @@ pkg syscall (openbsd-amd64-cgo), const EFER_NXE = 2048
 pkg syscall (openbsd-amd64-cgo), const EFER_NXE ideal-int
 pkg syscall (openbsd-amd64-cgo), const EFER_SCE = 1
 pkg syscall (openbsd-amd64-cgo), const EFER_SCE ideal-int
+pkg syscall (openbsd-amd64-cgo), const ImplementsGetwd = false
 pkg syscall (openbsd-amd64-cgo), const PMC5_PIPELINE_FLUSH = 21
 pkg syscall (openbsd-amd64-cgo), const PMC5_PIPELINE_FLUSH ideal-int
 pkg syscall (openbsd-amd64-cgo), const RTF_FMASK = 63496

diff --git a/src/syscall/mkall.sh b/src/syscall/mkall.sh
@@ -234,6 +234,12 @@ netbsd_amd64)
 	mksysnum="curl -s 'http://cvsweb.netbsd.org/bsdweb.cgi/~checkout~/src/sys/kern/syscalls.master' | ./mksysnum_netbsd.pl"
 	mktypes="GOARCH=$GOARCH go tool cgo -godefs"
 	;;
+netbsd_arm)
+	mkerrors="$mkerrors -m32"
+	mksyscall="./mksyscall.pl -l32 -netbsd -arm"
+	mksysnum="curl -s 'http://cvsweb.netbsd.org/bsdweb.cgi/~checkout~/src/sys/kern/syscalls.master' | ./mksysnum_netbsd.pl"
+	mktypes="GOARCH=$GOARCH go tool cgo -godefs"
+	;;
 openbsd_386)
 	mkerrors="$mkerrors -m32"
 	mksyscall="./mksyscall.pl -l32 -openbsd"

diff --git a/src/syscall/syscall_dragonfly.go b/src/syscall/syscall_dragonfly.go
@@ -216,6 +216,7 @@ func setattrlistTimes(path string, times []Timespec) error {
 //sys	writelen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_WRITE
 //sys	accept4(fd int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (nfd int, err error)
 //sys	utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error)
+//sys	getcwd(buf []byte) (n int, err error) = SYS___GETCWD
 
 /*
  * Unimplemented

diff --git a/src/syscall/syscall_freebsd.go b/src/syscall/syscall_freebsd.go
@@ -220,6 +220,7 @@ func setattrlistTimes(path string, times []Timespec) error {
 //sys	writelen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_WRITE
 //sys	accept4(fd int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (nfd int, err error)
 //sys	utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error)
+//sys	getcwd(buf []byte) (n int, err error) = SYS___GETCWD
 
 /*
  * Unimplemented

diff --git a/src/syscall/syscall_getwd_bsd.go b/src/syscall/syscall_getwd_bsd.go
@@ -0,0 +1,22 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build dragonfly freebsd netbsd openbsd
+
+package syscall
+
+const ImplementsGetwd = true
+
+func Getwd() (string, error) {
+	var buf [pathMax]byte
+	_, err := getcwd(buf[:])
+	if err != nil {
+		return "", err
+	}
+	n := clen(buf[:])
+	if n < 1 {
+		return "", EINVAL
+	}
+	return string(buf[:n]), nil
+}
diff --git a/src/syscall/syscall_netbsd.go b/src/syscall/syscall_netbsd.go
@@ -207,6 +207,7 @@ func setattrlistTimes(path string, times []Timespec) error {
 //sys	readlen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_READ
 //sys	writelen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_WRITE
 //sys	utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error)
+//sys	getcwd(buf []byte) (n int, err error) = SYS___GETCWD
 
 /*
  * Unimplemented

diff --git a/src/syscall/syscall_no_getwd.go b/src/syscall/syscall_no_getwd.go
diff --git a/src/syscall/syscall_openbsd.go b/src/syscall/syscall_openbsd.go
@@ -188,6 +188,7 @@ func setattrlistTimes(path string, times []Timespec) error {
 //sys	readlen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_READ
 //sys	writelen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_WRITE
 //sys	utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error)
+//sys	getcwd(buf []byte) (n int, err error) = SYS___GETCWD
 
 /*
  * Unimplemented

diff --git a/src/syscall/syscall_solaris.go b/src/syscall/syscall_solaris.go
@@ -29,15 +29,6 @@ type SockaddrDatalink struct {
 	raw    RawSockaddrDatalink
 }
 
-func clen(n []byte) int {
-	for i := 0; i < len(n); i++ {
-		if n[i] == 0 {
-			return i
-		}
-	}
-	return len(n)
-}
-
 func direntIno(buf []byte) (uint64, bool) {
 	return readInt(buf, unsafe.Offsetof(Dirent{}.Ino), unsafe.Sizeof(Dirent{}.Ino))
 }

diff --git a/src/syscall/syscall_unix.go b/src/syscall/syscall_unix.go
@@ -31,6 +31,16 @@ func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno)
 func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)
 func RawSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno)
 
+// clen returns the index of the first NULL byte in n or len(n) if n contains no NULL byte.
+func clen(n []byte) int {
+	for i := 0; i < len(n); i++ {
+		if n[i] == 0 {
+			return i
+		}
+	}
+	return len(n)
+}
+
 // Mmap manager, for use by operating system-specific implementations.
 
 type mmapper struct {

diff --git a/src/syscall/types_dragonfly.go b/src/syscall/types_dragonfly.go
@@ -125,6 +125,12 @@ type Dirent C.struct_dirent
 
 type Fsid C.struct_fsid
 
+// File system limits
+
+const (
+	pathMax = C.PATH_MAX
+)
+
 // Sockets
 
 type RawSockaddrInet4 C.struct_sockaddr_in

diff --git a/src/syscall/types_freebsd.go b/src/syscall/types_freebsd.go
@@ -210,6 +210,12 @@ type Dirent C.struct_dirent
 
 type Fsid C.struct_fsid
 
+// File system limits
+
+const (
+	pathMax = C.PATH_MAX
+)
+
 // Sockets
 
 type RawSockaddrInet4 C.struct_sockaddr_in

diff --git a/src/syscall/types_netbsd.go b/src/syscall/types_netbsd.go
@@ -110,6 +110,12 @@ type Dirent C.struct_dirent
 
 type Fsid C.fsid_t
 
+// File system limits
+
+const (
+	pathMax = C.PATH_MAX
+)
+
 // Sockets
 
 type RawSockaddrInet4 C.struct_sockaddr_in

diff --git a/src/syscall/types_openbsd.go b/src/syscall/types_openbsd.go
@@ -126,6 +126,12 @@ type Dirent C.struct_dirent
 
 type Fsid C.fsid_t
 
+// File system limits
+
+const (
+	pathMax = C.PATH_MAX
+)
+
 // Sockets
 
 type RawSockaddrInet4 C.struct_sockaddr_in

diff --git a/src/syscall/zsyscall_dragonfly_amd64.go b/src/syscall/zsyscall_dragonfly_amd64.go
@@ -1306,3 +1306,20 @@ func utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error)
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func getcwd(buf []byte) (n int, err error) {
+	var _p0 unsafe.Pointer
+	if len(buf) > 0 {
+		_p0 = unsafe.Pointer(&buf[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	r0, _, e1 := Syscall(SYS___GETCWD, uintptr(_p0), uintptr(len(buf)), 0)
+	n = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
diff --git a/src/syscall/zsyscall_freebsd_386.go b/src/syscall/zsyscall_freebsd_386.go
@@ -1304,3 +1304,20 @@ func utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error)
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func getcwd(buf []byte) (n int, err error) {
+	var _p0 unsafe.Pointer
+	if len(buf) > 0 {
+		_p0 = unsafe.Pointer(&buf[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	r0, _, e1 := Syscall(SYS___GETCWD, uintptr(_p0), uintptr(len(buf)), 0)
+	n = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
diff --git a/src/syscall/zsyscall_freebsd_amd64.go b/src/syscall/zsyscall_freebsd_amd64.go
@@ -1304,3 +1304,20 @@ func utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error)
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func getcwd(buf []byte) (n int, err error) {
+	var _p0 unsafe.Pointer
+	if len(buf) > 0 {
+		_p0 = unsafe.Pointer(&buf[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	r0, _, e1 := Syscall(SYS___GETCWD, uintptr(_p0), uintptr(len(buf)), 0)
+	n = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
diff --git a/src/syscall/zsyscall_freebsd_arm.go b/src/syscall/zsyscall_freebsd_arm.go
@@ -1304,3 +1304,20 @@ func utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error)
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func getcwd(buf []byte) (n int, err error) {
+	var _p0 unsafe.Pointer
+	if len(buf) > 0 {
+		_p0 = unsafe.Pointer(&buf[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	r0, _, e1 := Syscall(SYS___GETCWD, uintptr(_p0), uintptr(len(buf)), 0)
+	n = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
diff --git a/src/syscall/zsyscall_netbsd_386.go b/src/syscall/zsyscall_netbsd_386.go
@@ -1232,3 +1232,20 @@ func utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error)
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func getcwd(buf []byte) (n int, err error) {
+	var _p0 unsafe.Pointer
+	if len(buf) > 0 {
+		_p0 = unsafe.Pointer(&buf[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	r0, _, e1 := Syscall(SYS___GETCWD, uintptr(_p0), uintptr(len(buf)), 0)
+	n = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
diff --git a/src/syscall/zsyscall_netbsd_amd64.go b/src/syscall/zsyscall_netbsd_amd64.go
@@ -1232,3 +1232,20 @@ func utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error)
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func getcwd(buf []byte) (n int, err error) {
+	var _p0 unsafe.Pointer
+	if len(buf) > 0 {
+		_p0 = unsafe.Pointer(&buf[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	r0, _, e1 := Syscall(SYS___GETCWD, uintptr(_p0), uintptr(len(buf)), 0)
+	n = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
diff --git a/src/syscall/zsyscall_netbsd_arm.go b/src/syscall/zsyscall_netbsd_arm.go
@@ -1232,3 +1232,20 @@ func utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error)
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func getcwd(buf []byte) (n int, err error) {
+	var _p0 unsafe.Pointer
+	if len(buf) > 0 {
+		_p0 = unsafe.Pointer(&buf[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	r0, _, e1 := Syscall(SYS___GETCWD, uintptr(_p0), uintptr(len(buf)), 0)
+	n = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}